Fully Automatic Liquid Filling machines of known construction may be generally divided between two major architectural types or categories based upon their speed capabilities. Speed in this context refers to the number of containers or packages which are filled by the machine with a liquid product within a given time interval, most commonly expressed as containers per minute.
One major category of liquid filling machines are referred to as rotary fillers. These machines are characterized by their continuous motion, in which an array of filling nozzles or orifices rotate about a central spindle in a continuous circular manner. Empty containers to be filled with liquid are synchronously introduced into the machine and travel about the circumference of the structure. While each container is positioned under a circumferentially arranged filling nozzle, it is completely filled with liquid. Each container is so positioned for most of one complete revolution of the machine before it is synchronously removed from the machine. Practical limitations prevent the container from being filled for much more than 270 degrees of rotation of the 360 available. Nevertheless, it is apparent that even within this constraint the rotary filler is the fastest known architecture in that its motion is continuous and to increase its speed capabilities it is only necessary to increase the diameter of the machine, thus greatly increasing its circumference and thus allowing more room for additional filling positions. It can be shown that at a given rate of rotation, a rotary filler's container per minute output will increase in direct proportion to the increase in the number of filling positions fitted to the machine.
The second major category of liquid filling machines is referred to as in-line fillers. These machines may also be characterized by their motion which is asynchronous or intermittent. In this design, a plurality of containers to be filled typically are serially conveyed as a group into the machine and captured or indexed into position under filling nozzles or orifices. Most typically, the containers are then completely filled while they remain fixed and motionless. Upon completion of the fill, the container capture or indexing mechanism allows the filled containers to exit the filling area on the same conveyor which mediated their entry, and another plurality of containers are conveyed into position to be filled, and the sequence of events is repeated.
When compared to the rotary filling machine, the in-line architecture is clearly slower in potential containers per minute of output. It is possible to increase the speed of an in-line filler by the addition of filling positions. However, as each additional filling position is added, total machine output per minute increases at a decreasing rate per added position and eventually begins to decrease in total containers per minute of output. This is because as the number of containers to be filled in each machine cycle is increased, the indexing or transfer time of containers entering in to and out of the machine becomes an ever greater proportion of the machine's total cycle time. Thus, while the speed performance of an in-line machine can be improved, it is always at a fundamental architecturally based disadvantage when compared with a rotary design. The precise point at which attempts to speed up an in-line machine to approach or match rotary speeds varies technically and economically as a function of many variables, principle among them being the size of the liquid fill dose, the rheology of the liquid to be filled, and the size and shape of the container. In the vast majority of cases, the rotary design begins to dominate applications where speed requirements exceed 150 to 200 filled containers per minute, or where an in-line filler fitted with more than 12 to 16 filling positions is needed to satisfy required speeds.
Despite the limitation in speed associated with in-line automatic liquid filling machines of known type, these designs generally possess many technical capabilities of great merit (herein referred to as characteristics of merit) which are difficult or impractical or uneconomical to duplicate within the rotary filler design envelope. These capabilities include: the ability to simply and economically provide means to lower or dive the filling nozzles into the container for precise bottom-up or subsurface filling; the ability to vacuum aspirate the filling nozzles to prevent dripping following subsurface filling; the ability to readily and simply implement real time no container-no fill detection and inhibition functions, particularly in all filling positions; the ability to readily use many different types of filling nozzles, including bottom shut-off or positive shut-off filling nozzles; the ability to readily add or delete filling positions on the machine in a modular manner; the ability to readily implement a nitrogen (or other gas) pre-fill container purge, concurrent fill container gas purge, or post-fill container gas purge function; the ability to readily adjust filling volumes or levels or weights while the machine is operating (termed on the fly adjustment); the ability to separately and discretely adjust and alter the various machine functions and timing relationships; and the ability to locate and capture the neck or body of each container to assure proper position and alignment of the container with the filling nozzle during filling or to assure proper positioning of a filling nozzle for lowering onto or into the container prior to filling.
Additional important capabilities of in-line liquid filler designs of known type which are relatively distinct from known rotary designs include the typically greater speed and ease of product changeover of an in-line machine from one product type or container size to another. This fast changeover capability is a corollary to the relatively great and most significant distinction between in-line and rotary machines which is in regard to machine flexibility and versatility of usage which refers to the broad range of container sizes and shapes and the broad range of different types of liquid products which can be run on an in-line machine without need of change parts or machine additions or alterations. By way of example and illustration of this distinction, consider the PRO/FILL 3000 single lane in-line fully automatic liquid fillers manufactured by Oden Corporation of Buffalo, N.Y. A filling machine of this type, without change in physical design or fitments (sometimes referred to as change parts) of any kind, can completely and efficiently fill small round containers with two ounces of a low viscosity water-like liquid into oval shaped bottles, then can fill F-style 2.5 gallon jugs with motor oil, then can fill peanut butter into 12 oz. tapered glass jars, then can fill a thick cosmetic cream into four ounce square plastic containers, then can fill twenty ounces of honey into plastic containers shaped like a bear, then can fill highly foamy floor cleaner into plastic gallon jugs. No rotary filling machine of known type can meet this same test of flexibility and versatility.
Bearing in mind the above characteristics of merit of in-line liquid fillers, it is clear why numerous attempts have been made to increase the speed capabilities of in-line machines to rival rotary filler speeds. For comparative purposes, a single lane in-line machine of substantially standard type can be contrasted with known higher speed in-line derivatives. These derivative designs of known type include the dead plate pushover design, the shifting nozzle dual lane design, and the walking beam design. U.S. Pat. No. 3,036,604 discloses a bidirectional shuttle mechanism which moves containers onto a dead plate for filling. Thus dual lane design uses a dual lane feed, with the discharge merging into a single lane. This is a variation on the basic design of the prior art dead plate pushover design disclosed in FIG. 2 of this application. U.S. Pat. No. 3,322,167 discloses a shifting nozzle dual lane filler of the type disclosed in FIGS. 3 and 4 of this application. It is only through a comparative study and analysis of these known derivative designs that the unique and novel characteristics and advantages of the present invention will be clear. The prior art disclosed in this application will be discussed further after the following recitation of the objects of this invention, and the brief description of the various figures.